Improvement in safety-valves for dental vctlcanizers



tnited gieten FRANCIS It. MOORHEAD. OF GHANDLERSVILLE, OHIO.

Letters Patent No. 105,115, dated July 5, 1870.

IMPROVEMENT IN SAFETY-VALVES FOR DNTAL 'VULCANIZERS The Schedule referred to in these Letters Patent and making part of the same T o all whom it may concern:l

Be it known that I, FRANCIS R. MoonHnAD, of

"Chandlersville, in the county of Muskingum and State of Ohio, have invented certain Improvements in Dental Vnlcanizing Devices, of which the following is a speeiiication, reference being had to the accompanying drawing, in which- I4`igure 1 is a side elevation of my device, with a portion broken away.

Figure 2 is a top plan viewl of the same.-

My invention consists inthe novel construction and arrangement, in combination with dental vulcanizing devices, of a valve, with an adjustable spring, so that it shall serve as a safety-valve.

A represents the top of the vnlcanizer, upon which I mount, rigidly, two uprights b, having screw-threads cut upon their upper ends, and through the top A, midway between the posts, I make a conical hole or seat a., as shown in fig. 1.l

Into the seat a I insert the valve-head c, attached to or formed upon the lower end of the stem B, and over and around the stem B I place a spiral spring, C, the lower end of which rests upon the head c, as shown in fig. 1.

I then provide a bar, D, having three holes mader through it, and place it over the ends of the posts b and stem B, so that they pass through it, as shown in igs. 1 and 2, and then screw onto the ends of the posts b thumb-nuts d, as shown.

When thus arranged, the bar D lserves. both as a guide for the stem B and as a bearing for theupper end ofthe spring O, which latter is thereby caused to press the valve cinto the seat a, as shown in tig. 1.

By turning .the nuts d, the bar D may be forced down or allowed to rise, and thus the tension of the spring G be regulated at will.

The valve, thus constructed, vbeing applied to a vulcanizer, will remain closed until the pressure of the steam becomes sufficient to overcome the spring, when the valve c will rise, and .permit steam to escape through the hole or seat a, and thus will prevent the pressure' of the steam from becoming so great as to rupture the vesselfor the heat becoming so great as to injure the articles in process of vulcanization. The stem B Iprovide with graduations, and figures,

or characters, so that, when the bar D is forced down in line with any one of these lines or gradnations, the figure or character belonging thereto will show the pressure which the steam must attain to open the valve, this arrangement enabling the operator to set his valve for any pressure with ease and certainty. l

Having thus described my inveutiom v What I claim is 1. In combination with a dent-al vulcanizin'g device or apparatus, a movable safety-valve, when constructed and arranged to operate substantially as herein described, and for the purpose 'set forth.

2. The movable valve c, spring C, cross-bar D, and standards b, or their equivalents, in combination with a dental vulcanizer, when constructed and arranged to 'operate substantially as and for thc purpose set forth.

. FRANCIS R. MOORHEAD.

Witnesses:V

G. P. CRUMBAKER, F. W. Voer. 

